Genetics Exam 3

An RNA that does not encode a polypeptide is a(n) ______ RNA. Multiple choice question. -non-coding -immature -secondary -structural

non-coding

Besides DNA and histone proteins, ___-___ RNAs are a critical component of chromatin.

non-coding

Some errors create bulky distortions of the double helix. These errors are removed primarily by a DNA repair system called NER which stands for?

nucleotide excision repair

A main advantage of nonhomologous end joining is that it does not require a(n)

sister chromatid

Ultraviolet light causes the formation of crosslinked ??? in DNA

thymine dimers

Which statements are examples of how environmental factors may function as epigenetic regulators?

- Vernalization occurs when certain flowering plants are exposed to colder temperatures during the previous winter. - Exposure to tobacco smoke has been shown to alter DNA methylation and covalent modifications of specific genes in lung cells. - Body differences between queen bees and worker bees are caused by dietary differences.

Adult, wild-type mice with genotype AA for the Agouti gene will have what color coat hairs?

Brown with black tips

What is the basic repeating unit of chromatin

Nucleosome

What can cause double-strand Breaks?

X-rays Gamma rays Reactive oxygen species

Mice that are homozygous for the loss-of-function mutation in the Agouti gene will have _____ fur.

black

Ionizing radiation produces chemically reactive molecules known as

free radicals

In an average human individual, naturally occurring double-strand breaks occur at a rate of ??? per cell per day.

10-100

Which of the following are common uses of gene cloning?

Cloned genes can be introduced into bacteria to make medicines. Cloned genes can be used in trials of gene therapy. The expression of a cloned gene can be used to discover its cellular function.

What are nucleosomes composed of?

DNA wrapped around histone proteins

Which of these represents the correct order of steps during a typical DNA repair system?

Detection → Removal → Replication

The breakage of chromosomes is referred to as an ??? break

Double Stranded

The breakage of chromosomes is referred to as a(n) what break

Double stranded

True or False: During homologous recombination repair, the two broken ends of DNA are pieced back together.

False

True or false: Because epigenetics refers to heritable changes in gene expression, all epigenetic changes are examples of transgenerational epigenetic inheritance.

False

A recombinant DNA molecule has covalently linked DNA fragments from

At least two different sources

Trans-epignatic mechanisms are more commonly found in

Bacteria Single-Celled Eukaryotes

A particular gene to be cloned is often isolated from _____.

Chromosomal DNA

You would "blank" a gene to make many copies of that gene.

Clone

Which of the following are characteristics of euchromatin?

High level of gene expression Occupies a central position in the nucleus

Characteristics of heterochromatin include which of the following?

Highly Compact Structure Localized along the periphery of the cell nucleus Inhibition of gene expression

What are tautomers?

two molecules with the same molecular formula but different connectivity

During the normal course of DNA replication, the addition of a nucleotide that does not obey the AT/GC rule of base pairing creates a what?

base pair mismatch

A disadvantage of homologous recombination repair in eukaryotes is that it is dependent on

Sister chromatids, which are only available during part of the cell cycle.

In mice, the Agouti gene regulates ________.

The deposition of yellow pigment in hair

What is recombinant DNA technology?

The production of new arrangments of DNA

How do transcription factors contribute to epigenetic modification?

Transcription factors recruit chromatin modifying proteins, such as DNA methyltransferase.

A disadvantage of homologous recombination repair in eukaryotes is that it is dependent on ?

Uvr proteins, which require sunlight for their activity

Base excision repair is the main system used in the repair of _____

abnormal bases

The image shows the expected results following a cell fusion when a _______ mechanism is occurring..

cis-epigenetic

Some errors affect individual nucleotides and do not distort the DNA double helix. These errors are removed primarily by a DNA repair system called BER which stands for

Base excision

During the normal course of DNA replication, the addition of a nucleotide that does not obey the AT/GC rule of base pairing creates a ____?

base pair mismatch

Nucleotide Excision Repair (NER) is the main system used in the repair of ___.

bulky, helix distorting lesions

If an epigenetic change is maintained only at a given site and does not affect the expression of a gene elsewhere in the nucleus, it is a ______ mechanism.

cis-epigenetic

Which of the following are examples of epigenetics? Multiple select question. DNA mutation Covalent histone modification Localization of histone variants DNA translocation Chromatin remodeling DNA methylation

DNA methylation Localization of histone variants Chromatin remodeling Covalent Histone Modification

Which of the following are true regarding epigenetics? Multiple select question. Epigenetic changes are transmissible from cell to cell Variations of gene expression are unrelated to variations in the DNA base sequence Variations of gene expression result from mutations Epigenetic changes may be transmitted to offspring Variations are reversible from one generation to the next

Epigenetic changes are transmissible from cell to cell Variations of gene expression are unrelated to variations in the DNA base sequence Epigenetic changes may be transmitted to offspring Variations are reversible from one generation to the next

Which of the following is pharmaceutical product that is produced by bacteria expressing the human gene?

Insulin

How does ionizing radiation cause mutations?

It forms free radicals that can introduce breaks into the DNA molecule.

Which of the following is an example of epigenetic inheritance? Multiple choice question. -Methylation of DNA that occurs in an oocyte -Mutation of DNA in a sperm cell -A modified histone in a stem cell -A chromatin modification that causes cancer in a lung cell

Methylation of DNA that occurs in an oocyte

Activation of a gene that encodes a transcription factor capable of stimulating its own expression and/or the expression of other genes is an example of a ______ mechanism.

trans-epigenetic

What provides an error-free mechanism for repairing a DNA double-strand break.

Homologous recombination repair

Which type of epigenetic mechanism is shown in the image?

cis-epigenetic mechanism

When a cell repairs a double-strand DNA break by the mechanism of nonhomologous end joining, the original DNA sequence at the repair site ____.

may be changed by a small deletion

Which of the following terms is associated with ionizing energy? Gamma rays Long wavelength High energy Near Ultraviolet light Low energy Short wavelength

Gamma rays, High energy and Short wavelengths are all associated with ionizing energy

The variation of gene expression that is not related to the variation of the DNA, is transmissible, and is reversible is described as ???

epigenetics

Double-Strand breaks are typically repaired by which of the following?

homologous recombination repair and nonhomologous end joining

Genes that are expressed but do not encode polypeptides produce

Non-Coding RNA's

When there is a gain-of-function mutation in the mouse Agouti gene, the gene is ____ resulting in _______.

Over expressed ; yellow fur

Sunscreens usually contain organic compounds, such as ???, which absorb the harmful UV light.

Oxybenzone

Genomic imprinting and X-chromosome inactivation are examples of ??? mechanisms that occur during development

cis-epigenetic

What accounts for the wide array of coat colors seen in mice carrying the Aw allele of the Agouti gene?

Epigenetic modification of the promoter in the transposable element responsible for over expressing the Agouti gene

DNA methylation, chromatin remodeling, covalent histone modification, and localization of histone variants are all examples of molecular mechanisms that are involved in ???

Epigenetics

The variation of gene expression that is not related to the variation of the DNA, is transmissible, and is reversible is described as

Epigenetics

The replication of recombinant DNA molecules inside a host cell is one form of _______.

Gene Cloning

Mice that are homozygous for the loss of function in the Agouti gene will have black fu because ____.

Pheomelanin is not produced

A molecule that has covalently linked DNA fragments from at least two sources is called a?

Recombinant DNA

Which of the following are environmental factors that promote epigenetic changes? Multiple select question. Genomic imprinting Diet X chromosome inactivation Toxins Temperature

Temperature Toxins Diet

During DNA replication, a base that does not obey the normal AT/GC base pairing rule is added. This type of mutation is most likely corrected by which system?

mimatch repair system

During DNA replication, a base that does not obey the normal AT/GC base pairing rule is added. This type of mutation is most likely corrected by what repair system?

mismatch repair system

Which of the following are examples of base pair mismatches?

Adenine on parent strans and Cytosine on daughter strand & Cytosine on parent strand and Thymine on daughter strand & Cytosine on parent strand and Adenine on daughter strand